CHICAGO — The Chicago Bulls are running out — of time, of options, of second chances. The team’s trajectory had been established long before Saturday’s announcement that Zach LaVine would undergo season-ending surgery. The Bulls can’t keep their heads above .500. On the surface, LaVine’s injury might not appear to change much. He played only 25 games before he was ruled out for the year. The Bulls have logged some of their best basketball — a relative concept in a 23-27 season — with LaVine on the sidelines. But in reality, the decision made by LaVine to end his season could upend the Bulls’ p…